Facilities of public buildings and infrastructure services

Facilities of public buildings and services need to have more measures to protect this group of buildings when they are located in flood disaster areas. The retrofitting of buildings will work out on private housings and some small buildings, but the way of protection of public buildings will be different from the individual residents. However, public buildings are one of the important services for local people as a place to go for flood victims for evacuation and to use services like hospitals, schools, the fire department, the police station, the government building services, public and private banks and so on.

36 Hawkesbury's Flood Risk Management Plan: 15 years in the making; adapting a holistic approach to flood management in the Hawkesbury–Nepean region: complexities and perceptions of the agencies.

Practically, the hospital would require moving patients, children and the elderly outside that area to stay safe, when there is no flood protection. Those kinds of public buildings need special protection which is successfully achieved in European countries by having mobile flood protection walls, which can be installed as a boundary along the river.

By the suggestion of the FEMA (2007)³⁷ on flood proofing residential housings, the strategies were adapted on the basic wet proofing and dry proofing on flood areas. This method needs special consideration from case to case on appropriate areas or high settlements inadequately.

For example, experiences on the Danube in upper and lower Austria show the necessity of mobile flood barriers in areas which are built at predictable water currents. After the floods in 2002 and 2005 settlements were temporarily secured with mobile flood protection (Hochwasserleitwände) along the Danube (Rudolf-Miklau & Rimböck, 2016).

For the improved effectiveness of this measure, the mobile flood walls have to cooperate with:

1) The flood prediction mode 2) The warning und alarm system

3) The organization who is arranging the construction of the walls, for instance, the local fire brigades

Figure 6.13 Mobile flood protection (Hochwasserleitwände) (Rudolf-Miklau & Rimböck, 2016)

Also, many factors may concern the mobile flood barriers as an example in Ayutthaya in the world heritage site and the implementation of it should be much more in the public building in central flood plain areas of Thailand.

Other options for facility services are not only concerning the buildings itself, but the route of transportation which is also important to support the people and being able to evacuate and especially move the children and the elderly outside to a safe area.

37Federal Emergency Management Agency (FEMA): Selecting Appropriate Mitigation Measures for Flood prone structures. Washington DC: US Dept. of Homeland Security

 Bridge constructions

A bridge can be used mostly for convenience of commercial transportation. Moreover, in case of small floods, the well-designed bridges will help to bring some amount of water to flow more comfortably around the man-made obstacle.

Figure 6.14 Moveable Bridge: (Left) Folding Bridge; (Middle) Lift Bridge; (Right) Swing Bridge (Moveable Bridge, 2016)

The stream of the river especially in the case of a flood can be divided into several streams in different channels with a design of a swing bridge. When letting the water flowing smoothly around the bridge columns, it will reduce the pressure the columns have to withstand. The figure 6.14 shows some alternative designs for bridges, which will not be destroyed during a heavy flood or it may useful for flash flood as well. Because of Thailand knows many natural material made of the bridge on columns and the spacing, thus, the influence of the type of the bridge will be one of factors of consideration.

 Road infrastructure

A basic infrastructure will cause more trouble during flooding when the road is the main and only access. For example, road facilities which are linking two areas, representing a paved line, will create flood problems when high impact inundation floods occur for many days.

Especially, in the central business districts and / or emergency relief action areas, the situation can be severe. This will cause more problems on the economic development of the country and especially for financial institutions located on this area. From the economic point of view, such a road should also not provoke a negative aspect for transportation. In a case of a severe flood incoming, the road should be possible to either adapt to the new technical design and/

or offer more access from different directions.

As it can be seen in many flood disaster places, many main roads and local roads were cut by the heavy stream of water or high pressure from flood flowing. For example, the flood in 2011 in the Ayutthaya province submerged the main road which made it difficult to evacuate the people and bring them out of the risky flood area.

However, the regarding of the road facility issues is one important part of infrastructural public services.

According to the Pescadero Creek Road project in San Mateo, U.S.A. (2014), some of the suggestions for a solution on flooding that can be applied to the case of Thailand are the following:

 Creation of additional flow capacity at the road through construction of a channel dredging.

 Implementation of upland sediment control activities to reduce the amount of sediment delivered to the flood plain area.

 Reconnection or restoration of floodplains to absorb sediment and flood water energy, thereby reducing the transport of sediment downstream and limiting additional sediment inputs due to incision and bank erosion.

 Restoration or creation of a stable open channel to provide habitat connectivity for local fish and other aquatic species from upstream into the downstream.

The consideration of positive and negative aspects of the interaction between the roads and the flood demonstrates that floods can cause massive damage on the roads, on the transportation function, and beside that, the roads are also causing even more severe floods.

This is likely for roads in floodplain areas where they cause an impact on the infrastructure development.

Therefore, the development of the roads in the flood plain will provide more solutions to evacuate flood victims, provide safety places for residential houses and the economic development area will not hamper.